Antimicrobials for GI - Parker

most acute diarrhea needs what

trick question! nothing. no antibiotics, just resolve on its own

when to tx pts with acute diarrhea

invasive

hospitalized >3 days

bloody diarrhea

severe illness

campy jejuni tx

azithromycin or erythromycin (imagine a crow on the turkey spit on sketchy)

campy fetus

*hint

gentamicin

alt: amp or imipenem

ecoli o157:h7 tx

bloody diarrhea no fever

NO ANTIBIOTICS → worsens condition. its the toxin not the bacteria

listeria tx

ampicilin or TMP/SMX

salmonella tx

adults→ ciprofloxacin or levofloxacin

kids → azithromycin

shigella tx

hint*

cipro or levofloxacin

spirochetosis tx

(cholera assoc anaerobic spirochete)

metronidazole

benefits of AB unclear for this

vibrio cholera tx

doxy/tetracycline or FQ or marcolide

REHYDRATE MY DUDES

vibrio parahaemolyticus tx

FQ or tetracycline

vibrio vulnificus tx

severe wound infection and septicemia, must treat

ceftriazone or ceftazidine + doxy/minocycline

yersinia enterocolitica

enterocolitis tx

FQ or TMP/SMX

yersinia enterocolitica septicemia tx

ceftriaxone + gentamicin

c diff 1st line tx

oral vancomycin

recurrent c diff tx

fidaxomicin (macrolide)

ampicillin, clindamycin, FQ, repeat antibiotics can lead to what

cdiff assoc diarrhea (CDAD)

typhoid fever (salmonella) tx

not in asia

FQ (cipro/levo)

typhoid fever tx In asia

ceftri., azithromy., or chlorampenicol

get your vaccines people

ETEC (travelers diarrhea) tx

FQ

azithro for kids/preggos

rifaximin is newer, sim to rifampin

ok to use antimotility → loperamide

prevent ETEC

levoflox +loperamide/rifaximin/doxycycline

whipples disease tx

doxy + hydroxy for 1 year then doxy forever

outpatient diverticulitis/abscess

tmp/smx

cipro

levofloxacin+metro

inpatient mild/moderate for diverticulitis/abscess

pip/taz or ertapenem or moxifloxacin

(don’t need metro bc its spectrum is that of FQ and metro)

inpatient severe diverticulitis/abscess

imipenem, meropenem, doripenem

severe PCN/ceph allergy with severe inpatient diverticulitis/abscess

aztreonam + metronidazole

primary bacterial peritonitis

pip/taz or ceftriaxone or ertapenem

2ndary prophylaxis for primary bacterial peritonitis

TMP/SMX or ciprofloxacin (high rate of recurrence which is why prophylax needed)

secondary bacterial peritonitis, mild mod

pip/tazo

secondary bacterial peritonitis, severe

carbapenem or metro + amp + aminoglycoside

cirrhosis and variceal bleeding

ciprofloxacin is 1st line, alternative is ceftriaxone

hepatic abscess, anaerobes usually

metronidazole + ceftriaxone

cefoxitin

antipseudomonal PCN

FQ

urease producing gut bacteria, hepatic encephalopathy

RIFAXIMIN yuh

gallbladder disorders

1st pip/tazo or amp/sulbactam

very severe → carbapenem + adequate drainage

binds beta subunit of bacterial dependent RNA polymerase → inhibits bacterial RNA synthesis

moa of rifaximin → ETEC, hep. enceph., IBS-D

Macrolide, inhibits RNA synthesis by RNA polymerases → inhibits protein synthesis

ribosomal inhibition 50S

fidaxomicin MOA

CDAD use, recurrence

little to no AE

inhibits cell wall synthesis in gram+

use orally for CDAD (1st)

oral vancomycin (not systemic, stays in gi tract)

inhibits bacterial cell wall synthesis by inactivating PBPs

gram+ and gram- cocci

penicillin moa

beta lactam, messes with transpeptidase reaction → synthesis of petidoglycan layer

gram+ gram - and anaerobes

carbapenems

binds 50s subunits, inhibits protein synth

doc for legionnaires disease

QT prolong → torsades, cyp450 inhibitor

macrolides

messes up dna gyrase and topoisomerase iv

ci in preggos/kids/g6pd deficiency

ae: tendon rupture, cdiff,

fluorquinolones

also binds 50s ribosomal subunit and inhibits peptidyl transferase activity. betalactamase bacteria

ae → c diff

clindamycin

inihibts dihydrofolate reductase

inhibits incorporation of PABA into dihydropteric acid

no no in babies and 3rd trimester → kernicterus

TMP/SMX

orange pee

rifampin